Viscous fan shaft bearing removal

Leading on from a thread on another forum where I asked if anyone had taken one of these bearings out. The general answer being no, I thought I would have a go my self - being the inquisitive person I am.

First off, a warning. Do not try and press the shaft out of the bearing! Photo No.4 shows why....

So to get the bearing out, first you have to press the shaft through the flange on the front of the bracket, pushing in the red arrow direction, and supporting from the green:



Next bit is a pain in the arse, as you have to find a way for holding the bracket on its back side, and its not flat, at all. Once you've done that push the shaft and bearing out together, in the direction of the red arrow.



You should then end up with this:



Now looking at this you can see its a bit of a specialist bearing. I'm calling the front of the bearing the end at which the outside black groove is closest too. I wanted to see what it did and went to press the shaft out of the bearing.

This was followed by a loud bang and bits of flying bearing casing and ball bearings.



The ball bearings sit in a groove cut into the shaft, and a groove cut into the bearing casing at the 'back' of the bearing. There is also a roller bearing at the front of the bearing.

I now know the correct way of dismantling the bearing, but TBH its pretty pointless doing so. I'm guessing the shaft and the bearing come as one from Chrysler/Jeep, but have yet to find out.

Heres the way of taking it apart, for those that are interested:

Firstly the seal comes off the back of the bearing:


Then you lever out the plastic cage:


And you can then move the balls to one side of the bearing, tilt it slightly, and take them out.


There is meant to be six balls... the rest didn't hit me :roll:

Good post with pics, BigGaz.:cheers:
The bearing and shaft are indeed supplied as one unit.
I bought one last summer but didn't install it. (The noise
was coming from the A/C clutch and not the bearing.)

These are actually waterpump bearings in some
applications.

are you going to post pics of installing the replacement bearing too?

Runnin'OnEmpty said:

The bearing and shaft are indeed supplied as one unit.
I bought one last summer but didn't install it.

Click to expand...

Would you have a part number for that?

Talyn said:

Would you have a part number for that?

Click to expand...

It's an NSK brand:
part number 885586

Bought from Motion Industries.

Don't remember the cost exactly; maybe $25-$30 ...?

Anyone know of an online source for the NSK 885586 bearing?

i cut the whole assembly off with an angle grinder when i fitted my twin electric fans, you have no idea how smooth and responsive the motor can be till you get rid of that mechanical fan

Ewenm said:

i cut the whole assembly off with an angle grinder when i fitted my twin electric fans, you have no idea how smooth and responsive the motor can be till you get rid of that mechanical fan

Click to expand...

What year xj do you have? And how did you route the belt? What length was the belt you used as well?

mine is a '94, but as it is Australian delivered it may be a '93 and RH drive, i followed the instructions on "go jeep" a local guy who has done heaps of stuff and set up his own web site. by following his instructions i didn't need a new belt, just used the old one, however as my car is RH drive the PS pump and the A/C are in different locations to yours

but it was among the top mods in my opinion, i retained the electric A/C fan and added a 16" or 18" fan ( cant remember) with an adjustable thermostat, the type where the capillary tube goes into the top radiator hose, works well for me

even in our hot Queensland summers the fans keep the car cool towing an 18 foot bow rider

oh the reason for cutting out the mechanical fan bearing and post was for clearance, theres not a lot of room in there

Various years use different bearing + shaft assemblies.

It is even worse than alluded to by Runnin'OnEmpty - at least if you can't get the bearing+shaft from the aftermarket. The dealer considers the whole bracket, bearing, shaft, and flange to be a single unit and wants well over $200 for it last time I checked!

I ended up pressing the good bearing out of a junk bracket I had (had bolts broken off in it), pressing the bad bearing out of a good bracket I had, and then pressing the good bearing into the good bracket. Except it wouldn't fit in my press, so by "press" I mean muttered a lot of very unkind things about Chrysler/Jeep engineers and bashed it in with a 4lb hammer, expecting fully to need to get another whole unit from the JY a few days later due to false brinnelling. It certainly did the bearing no favors, but after a few days the whining/screaming from the flattened spots on the balls went down, and it's been running smoothly since then... I did get a spare from the junkyard on my next trip just in case it goes south again however.

What exactly were they thinking when they came up with this design? I mean, seriously?

They were thinking that cars are dispoable, and wouldnt be on the road in 2013. We were supposed to hace flying cars by now.

Any chance of having some machining done, and run a bearing or three that are readily available fitted?

Ewenm said:

mine is a '94, but as it is Australian delivered it may be a '93 and RH drive, i followed the instructions on "go jeep" a local guy who has done heaps of stuff and set up his own web site. by following his instructions i didn't need a new belt, just used the old one, however as my car is RH drive the PS pump and the A/C are in different locations to yours

but it was among the top mods in my opinion, i retained the electric A/C fan and added a 16" or 18" fan ( cant remember) with an adjustable thermostat, the type where the capillary tube goes into the top radiator hose, works well for me

even in our hot Queensland summers the fans keep the car cool towing an 18 foot bow rider

oh the reason for cutting out the mechanical fan bearing and post was for clearance, theres not a lot of room in there

Click to expand...

Can you get a pic of your engine bay/belt routing please?
I udnerstand that it is different, but how the same belt with one less pulley?
Trust me, I know that there is very little room. I need to swap out the housing on one of the fans, but the pulley is really close. Got a shorter serp belt today to bypass it.

kastein said:

Various years use different bearing + shaft assemblies.

It is even worse than alluded to by Runnin'OnEmpty - at least if you can't get the bearing+shaft from the aftermarket. The dealer considers the whole bracket, bearing, shaft, and flange to be a single unit and wants well over $200 for it last time I checked!

I ended up pressing the good bearing out of a junk bracket I had (had bolts broken off in it), pressing the bad bearing out of a good bracket I had, and then pressing the good bearing into the good bracket. Except it wouldn't fit in my press, so by "press" I mean muttered a lot of very unkind things about Chrysler/Jeep engineers and bashed it in with a 4lb hammer, expecting fully to need to get another whole unit from the JY a few days later due to false brinnelling. It certainly did the bearing no favors, but after a few days the whining/screaming from the flattened spots on the balls went down, and it's been running smoothly since then... I did get a spare from the junkyard on my next trip just in case it goes south again however.

What exactly were they thinking when they came up with this design? I mean, seriously?

Click to expand...

I know that the brackets are different between years, but when I checked recently, because I need one badly it was almost 400$ from the dealer for a renix one. Thankfully I found a later model one from a member in the PNW chapter. Will give me an excuse to relocate/swap in a higher output alternator. May have a line on a GC/D 160 A alt. if that falls through, considering getting a pad mount alternator, and using a plate to make an adapter bracket if the pattern differs from the ac/pulley bracket.

souske said:

They were thinking that cars are dispoable, and wouldnt be on the road in 2013. We were supposed to hace flying cars by now.

Any chance of having some machining done, and run a bearing or three that are readily available fitted?

Click to expand...

I don't give a hoot about flying cars, all kinds of people would die to already stupid drivers falling out of the sky from running out of fuel.
What I want is a hoverboard.

I am pretty sure that the alternator bracket is 100% independent of the AC compressor + mechanical fan bearing bracket. The only issue swapping from a RENIX bracket to an OBD1 bracket (afaik) is that you'll need a later AC compressor to be able to bolt it on, but I think the lines from a 91-93/94 or so AC compressor should fit a RENIX AC system anyways... not sure...

Oh, and 95 down vs 96 up A/C + mech fan brackets only differ in whether they have a boss to bolt an idler pulley to, and (possibly, but not sure) the bearing/shaft assembly that is required for the mech fan. 95 down have the boss for the idler pulley, the new tensioner setup in 96 eliminated that tensioner. You can use a 91-95 A/C bracket on a 96 and up with no real issues if you just remove the idler pulley.

Ewen, I pounded out the shaft instead of cutting the nose off when I went to the 2 stock e-fan setup. I had to grind a corner of the alternator bracket and some metal above the 0* timing mark and used a 2045mm belt. There is only a 1/4 wrap on the alt, but it works and yes you can feel the difference w/o the mech fan drag.